We've been thinking about the same for some time, and I put together a WIKI page discussing the need for such a pipeline. Feel free to edit, extend and discuss inside the WIKI.

It need not be a part of Solr as such, but it is crucial that there is one preferred pipeline where the community can gather their effort in writing re-usable processing stages.

Jan Høydahl, search solution architect
Cominvent AS - www.cominvent.com

On 18. apr. 2011, at 12.37, Roland Villemoes wrote:

Hi All,
I know this question may have been asked before – but I really did not find any usable answers browsing the archives. So I have to try the developer list here.
We at Alpha Solutions often need a Pipeline for handling crawling, analyzing and routing before we hit the UpdateRequestHandler in Solr. I know we could actually use the UpdateRequestHandler for this - but often we like to perform all these tasks before hitting Solr.
We have been using OpenPipeline which does offer a GUI also which makes it rather nice to administer (if you tweak the GUI a bit!). I does seem though, that OpenPipeline will not really get going. Nothing happens, and there is not really any community around it – and it doesn’t seem that the guys that’s behind this will ever move this further.
So we are looking around towards other “pipeline” projects that can work well with Solr.
So – does any of you have any ideas on this? Any recommendations? Or any plans of this for Solr?
Thanks a lot
Med venlig hilsen / Best regards

Roland Villemoes
Tel: (+45) 22 69 59 62

Alpha Solutions A/S
Borgergade 2, 3.sal, DK-1300 Copenhagen K
Tel: (+45) 70 20 65 38

** This message including any attachments may contain confidential and/or privileged information
intended only for the person or entity to which it is addressed. If you are not the intended recipient
you should delete this message. Any printing, copying, distribution or other use of this message is strictly prohibited.
If you have received this message in error, please notify the sender immediately by telephone
or e-mail and delete all copies of this message and any attachments from your system. 
Thank you.